[Ips-dsgr] IPS Daily Report - 22 May 07
rwc
rwc at ips.gov.au
Wed May 23 09:51:51 EST 2007
SUBJ: IPS DAILY SOLAR AND GEOPHYSICAL REPORT
ISSUED AT 22/2330Z MAY 2007 BY IPS RADIO AND SPACE SERVICES
FROM THE AUSTRALIAN SPACE FORECAST CENTRE
SUMMARY FOR 22 MAY AND FORECAST FOR 23 MAY - 25 MAY
STATUS INDICATORS SOL:GREEN MAG:** YELLOW ** ION: GREEN
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1A. SOLAR SUMMARY
Activity 22 May: Very low
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number for 22 May: 72/8
1B. SOLAR FORECAST
23 May 24 May 25 May
Activity Very low Very low Very low
Fadeouts None expected None expected None expected
10.7cm/SSN 75/13 75/13 75/13
COMMENT: Solar activity was very low over the past 24 hours with
just three B-class flares from spot region 956 (N03W47) the most
significant of which was a long-duration B3.9 at 22/1447UT. This
flare was associated with a Type-II radio sweep and a weak CME
evident in SOHO LASCO imagery with an estimated velocity of 585km/s.
The solar wind speed has returned to its pre-coronal hole level
of around 440km/s. A solar sector boundary crossing occurred
at 21/2220UT indicated by a change in polarity of the Interplanetary
Magnetic Field (IMF) 'phi' angle. IMF Bz was steady and strongly
Northward until ~0900UT when it turned southwards. It has been
southward for the last 7 hours producing enhanced merging at
high latitudes. A recurrent equatorial coronal hole has passed
solar central meridian and should move into geoeffective position
on 24 May.
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2A. MAGNETIC SUMMARY
Geomagnetic field for Australian Region 22 May: Quiet to Unsettled,
Minor Storm at high latitudes.
Estimated Indices 22 May : A K
Australian Region 8 12222233
Darwin 8 22222232
Townsville 10 22223233
Learmonth 14 22333343
Camden 8 11222233
Canberra 9 11232233
Hobart 10 12233133
Casey(Ant) 7 12222232
Observed Regional daily pc3 Indices 22 May :
Darwin 0 (Quiet)
Townsville 0 (Quiet)
Learmonth 0 (Quiet)
Camden 0 (Quiet)
Canberra 0 (Quiet)
Hobart 18 (Quiet)
Pc3 pulsations are high frequency (10-45 second period) variations
of the Earths magnetic field. Daily pc3-indices are the daily sum
of 20 minute pc3-indices for that station and have been shown to be
well correlated with rejection of high resolution aeromagnetic
survey flight-line data.
NOTE: Indices may have been generated from data obtained in
cooperation with the following organisations: Geoscience Australia,
University of Newcastle Space Physics Group, Australian Government
Antarctic Division and Space Environment Research Center, Japan.
Estimated AFr/Ap Indices 22 May : A
Fredericksburg 5
Planetary 8
Observed AFr/Ap Indices 21 May : A K
Fredericksburg 6
Planetary 6 3100 1123
2B. MAGNETIC FORECAST
Date Ap Conditions
23 May 10 Quiet to unsettled
24 May 16 Unsettled to active
25 May 22 Active
COMMENT: The geomagnetic field was generally Quiet to Unsettled
over the UT day. Minor Storm conditions were observed at high
latitudes after 22/1800UT in response to a steady southwards
Interplanetary Magnetic Field (IMF) 16-23UT producing enhanced
and steady reconnection. The Unsettled conditions were due to
the predominantly southwards IMF in the second half of the UT
day. A solar sector boundary crossing at 21/2220UT produced an
isolated period of Unsettled conditions late on May 21. The weak
CMEs of 19 May produced no obvious shocks in the solar wind 22
May. Expect continuing Quiet- Unsettled geomagnetic conditions
23 May. A recurrent coronal hole is expected to move into geoeffective
position 24 May. This coronal hole produced Active to Minor Storm
conditions on its last two rotations and is expected to result
in Unsettled to Active conditions 24-25 May with isolated periods
of Minor Storm conditions possible at high latitudes.
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3A. GLOBAL HF PROPAGATION SUMMARY
Latitude Band
Date Low Middle High
22 May Fair Normal Normal
PCA Event : No event.
3B. GLOBAL HF PROPAGATION FORECAST
Latitude Band
Date Low Middle High
23 May Fair Normal Normal
24 May Normal Normal Normal-fair
25 May Normal Normal Normal-fair
COMMENT: Frequencies were generally near predicted monthly values
in the Australian region 22 May and enhanced in the Antarctic.
20-30% MUF depressions were observed in the Equatorial PNG/Niue
region. Spread-F was observed at some S.Aus/NZ stations overnight
and widespread sporadic-E was observed at most Aus stations after
dusk. Expect frequencies to be mostly near predicted monthly
values 23 May with the exception of the PNG/Niue region which
may experience further MUF depressions. Further spread-F likely
at S.Aus/NZ stations overnight. Maximum Useable Frequencies are
expected to be enhanced 24-25 May as the winter ionosphere responds
to enhanced geomagnetic activity.
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4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
Date T index
22 May 10
Observed Australian Regional MUFs
Equatorial PNG/Niue Region:
Depressed by 20% during local day,
Depressed by 25% during local night.
Northern Australian Region:
Mostly near predicted monthly values,
Southern Australian and New Zealand Region:
Near predicted monthly values during local day,
Enhanced by 20% during local night.
Antarctic Region (Casey/Scott Base/Davis/Mawson):
Enhanced by 45% over the UT day.
Predicted Monthly T index for May: 9
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
Date T index MUFs
23 May 12 near predicted monthly values
24 May 26 10 to 20% above predicted monthly values
25 May 30 10 to 20% above predicted monthly values
COMMENT: HF conditions were mostly normal 22 May at mid latitudes.
Equatorial stations suffered 25-30% MUF depressions over the
UT day. Mid-high latitude stations were enhanced overnight. Periods
of Spread-F were again observed overnight at mid- high latitude
stations. Widespread occurrence of Sporadic-E was observed at
Low and Mid-latitudes for a 2-3 hour period after dusk. HF conditions
are expected to be mostly normal 23 May at mid-high latitudes.
Low latitudes may experience further depressions. MUF enhancements
are expected 24-25 May as the winter ionosphere responds to enhanced
geomagnetic activity.
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5. SPACE ENVIRONMENT SUMMARY
GOES satellite data for 21 May
Daily Proton Fluence >1 MeV: 1.4E+06
Daily Proton Fluence >10 MeV: 1.6E+04
Daily Electron Fluence >2 MeV: 3.70E+07 (normal fluence)
Electron Fluence Daily Deep Dielectric Discharge Probability: 5%
Fluence (flux accumulation over 24hrs)/ cm2-ster-day.
X-ray background: A2.2
ACE Satellite Solar Wind Day Averaged Data for 21 May
Speed: 503 km/sec Density: 1.2 p/cc Temp: 45200 K Bz: 2 nT
(Courtesy Space Environment Center, Boulder USA)
ACE data can be incorrect during strong proton events.
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